Small polypeptides are expected to become cancer vaccines

Scientists are working on a small peptide of 10-50 amino acids that could be used as a potential cancer vaccine Because they may be safer, more effective and cheaper than monoclonal antibody drugs and small molecule inhibitors that are now commonly used in the treatment of malignant tumors Researchers from the comprehensive cancer center of Ohio State University have identified two regions of HER1 / EGFR, an important protein responsible for cancer cell growth, metastasis and poor prognosis of patients, which can be used as targets for peptide agents There are many receptor molecules on the surface of cancer cells, which can be activated by growth factors in the blood, and released by other cells in the tumor to activate tumor growth Dr pravin kaumaya, director and chief investigator of vaccine research and development department, said: "our findings can guide the development of new peptide vaccines and mimicry inhibitors targeting HER1 protein in tumors of multiple sites (such as breast, lung, intestine, head and neck), which can overcome the shortcomings of many antibody drugs, such as cetuximab." "Such polypeptide agents can make the development of combined immunotherapy possible, either by using HER2 vaccine or VEGF therapy, so as to avoid the secondary treatment failure that drug resistance mechanism or antibody treatment sometimes face," kaumaya said HER1 and HER2 are members of the epithelial growth factor (EGF) family of cell surface receptors These receptors play a central role in the development of many human cancers, such as breast, lung, colorectal and head and neck cancers Kaumaya and his colleagues evaluated three sequences of peptides and identified one of the most specific and immunogenic (which can cause the strongest immune response in experimental animals), so it is particularly suitable as a vaccine and therapeutic agent These three sequences, or epitopes, are located at the contact sites of HER1 and growth factors The key technical findings of this study are: 1 Two sequences (382-410 and 418-435) are most suitable for cancer treatment or as cancer vaccine; 2 The 382-410 epitope overlaps the binding site of cetuximab, an antibody that inhibits HER1 binding, while the 418-435 epitope strongly inhibits tumor growth in transplanted breast and lung cancer animal models 3 The vaccine is highly immunogenic and can establish immune memory in rabbit model "Overall, our results show that the 418-435 epitope has great potential as a vaccine or drug for the treatment of HER1 overexpression like cancer," kaumaya said The results of the study were published in the Journal of immunology.